Portable compound battery unit management system

Abstract

A portable compound battery unit management system comprises a portable high capacity battery unit, a main power battery unit, and a DC converter. The portable high capacity battery unit has a built-in battery management means and is connected to the DC converter. The main power battery unit supplies power to a motor which in turn drives the vehicle, and contains another battery management means or a device for limiting maximum output current, or provides the DC converter and a motor controller installed behind with battery information required to operate the vehicle. The DC converter transfers the electrical energy of the portable high capacity battery unit to the main power battery unit, or converts output power of the portable high capacity battery unit to a necessary power required to operate the motor controller, wherein it has boost up or buck down function of voltage to match the voltage difference between the two battery units. With this scheme, the effectively combined portable high capacity battery unit and main power battery unit are very convenient to supply mechanical power for driving the motor bicycle to travel desired distance with a low operation and maintenance cost.

1. A portable compound battery unit management system for an electrically powered vehicle, comprising:
 a DC converter coupled to a motor controller, said motor controller being coupled to a propulsion motor of the vehicle; 
 a main power battery unit coupled to said DC converter for supplying power to drive said propulsion motor, said main power battery unit including a plurality of cells coupled in series and a battery management means for limiting a maximum output current of said series coupled cells, said battery management means being coupled to said DC converter and said motor controller to provide battery operational data thereto; and 
 at least one interchangeable and portable high power density supplemental battery unit detachably coupled to the vehicle and having a built-in battery management means having a low capacity cut-off and being connected to said DC converter, said supplemental battery unit being selectively removed for charging independently of said main power battery unit with an external charger, said supplemental battery unit powering said propulsion motor in parallel with said main power battery unit through said DC converter for sharing the power demand thereof; 
 said DC converter converting an output voltage of said supplemental battery unit to match an output voltage of said main power battery unit and selectively coupling said supplemental battery unit to said main power battery unit. 
 
   
   
     2. The battery unit management system of  claim 1 , wherein at least one supplemental battery unit includes a battery type selected from the group consisting of a high capacity Li ion battery, a Li Polymer battery, and an exchange type fuel cell. 
   
   
     3. The battery unit management system of  claim 1 , wherein said main power battery unit includes a battery type selected from the group consisting of a Pb/CaSO4 battery, a Ni-mH battery, a Ni—Zn battery, a Li—Mn/Li—Co battery, and a Li-Polymer battery. 
   
   
     4. The battery unit management system of  claim 1 , further comprising logic to judge whether electric energy stored in said two battery units is enough to operate said motor controller. 
   
   
     5. The battery unit management system of  claim 1 , wherein said DC converter includes control functions of checking whether a residual charge of said supplemental battery unit is zero, whether said main power battery unit is fully charged, and whether said motor controller is in a working state. 
   
   
     6. The battery unit management system of  claim 1 , further comprising a second supplemental battery unit for interchange with said supplemental battery unit coupled to said DC converter when said supplemental battery unit coupled to said DC converter has been discharged.